tbuckley/cabot-search huggingface dataset:
Abstract P1009: Size And Distribution Of Human Cardiac Tissue Grafts Following Transendocardial Delivery Of Committed Cardiac Progenitors In A Swine Ischemic Heart Failure Model
Authors: Sushmita Roy, Tianhua Zhou, Eric G Schmuck, Yukihiro Saito, James Conklin, Timothy A Hacker, Patrick C Hsieh, Chad Koonce, Amish N Raval, Timothy Kamp
Journal: Circulation Research (2022)

Introduction: iPSC-derived committed cardiac progenitor cells (CCP) have exciting potential to remuscularize infarcted myocardium; however, little is known about CCP engraftment and differentiation following injection. We hypothesized that transendocardial injection (TEI) of CCPs with an injectable cardiac fibroblast derived extracellular matrix (ECM) retention agent would result in cardiac tissue grafts in an immunosuppressed porcine ischemic heart failure (HF) model. Methods: Coronary artery balloon-occlusion myocardial infarction was induced in Yucatan mini-swine. After 1 month, 300M CCPs with and without 50 mg ECM particles were delivered in 15 intramyocardial injections to the border zone and infarct zone using a steerable Myostar injection catheter with NOGA XP mapping. Immunosuppressed swine were sacrificed up to 2 months following treatment. Hearts were systematically sectioned and stained for human nuclear antigen (Ku80) and cardiac troponin I/T to define the area and distribution of human grafts and cardiomyocyte content. Results: Clusters of human grafts composed of predominantly troponin positive cardiomyocytes were observed in the infarct, at the infarct border, and in adjacent healthy tissue. Overall, 21/25 (84%) of treated pigs had human cardiac tissue grafts. In the current analysis, grafts were identified in 11/12 (91.6%) and 10/13 (76.9%) of pigs in the CCP+ECM and CCP, respectively (see Figure). The observed mean graft area was 62,930 ± 40,332 μm 2 and 185,200 ± 329,080 μm 2 per pig in the CCP+ECM and CCP only groups, respectively (p=0.23). Conclusion: In an immunosuppressed swine ischemic HF model, TEI of CCPs ± ECM yields persistent human cardiac tissue grafts composed of predominantly of cardiomyocytes in both infarcted and non-infarcted regions of the myocardium up to 2 months following treatment.
Abstract P3049: Age-independent Cardiac Protection By Pharmacological Activation Of Beclin-1 During Endotoxemia And Its Association With Energy Metabolic Reprogramming In Myocardium-A Targeted Metabolomics Study
Authors: Matthew Kim, azadeh nikouee, Raymond Zou, Di Ren, Zhibin He, Ji Li, Lu Wang, Danijel Djukovic, Daniel Raftery, Hayley J Purcell, Daniel Promislow, Yuxiao Sun, Mohammad Goodarzi, Qing-Jun Zhang, Zhi-Ping Liu, Qun S Zang
Journal: Circulation Research (2022)

Background: We previously showed that Beclin-1-dependent autophagy is cardiac protective in a rodent model of endotoxemia using young adult mice. In this report, we compared the potential therapeutic effects of pharmacological Beclin-1 activating peptide, TB-peptide, on the cardiac outcomes of young adult and aged mice during endotoxemia. We further examined alterations in myocardial metabolism induced by lipopolysaccharide (LPS) challenge with and without the TB-peptide treatment. Methods: C57BL/6J mice of 10-week and 24-month-old were challenged by LPS at doses at which cardiac dysfunction occurred. Following the treatment of TB-peptide or control vehicle, heart contractility, circulating cytokines, and myocardial autophagy were evaluated. A targeted metabolomics assay was applied to analyze cardiac metabolism. Results: TB-peptide boosted autophagic response, attenuated cytokine production, and improved cardiac performance in both young and aged mice during endotoxemia. A targeted metabolomics assay was designed to detect a pool of 361 known metabolites, of which 156 were detected in at least one of the heart tissue samples. LPS-induced impairments were found in glucose and amino acid (AA) metabolisms in mice of all ages, and TB-peptide provided ameliorative effects to rescue these alterations. However, lipid metabolites were upregulated in the young group but moderately downregulated in the aged by LPS, suggesting an age-dependent response. TB-peptide mitigated LPS-mediated trend of lipids in the young mice but provided little effect on the aged ones. Conclusion: Pharmacological activation of Beclin-1 by TB-peptide protects the heart in both young and aged population during endotoxemia, suggest a therapeutic potential for sepsis-induced cardiomyopathy. Metabolomics analysis suggests that this age-independent protection by TB-peptide is associated with reprograming of energy production via glucose and AA metabolisms.
Abstract P1083: Calcium-dependent Proteolysis Of Mitochondrial Opa1 By Calpain Contributes To Arrhythmogenesis In Catecholaminergic Polymorphic Ventricular Tachycardia
Authors: Shanna Hamilton, Radmila Terentyeva, Roland Veress, Fruzsina Perger, Zuzana Nichtova, Benjamin Martin, Sandor Gyorke, Andriy Belevych, Gyorgy Csordas, Dmitry Terentyev
Journal: Circulation Research (2022)

Intracellular Ca 2+ cycling in ventricular myocytes (VMs) is tightly linked to mitochondrial metabolic output, and disturbances in this coupling contribute to cardiac arrhythmias. We recently demonstrated in the heritable arrhythmia syndrome catecholaminergic polymorphic ventricular tachycardia (CPVT), the arrhythmogenic phenotype is revealed by oxidation of the cardiac ryanodine receptor (RyR2) calcium release channel by mitochondrial reactive oxygen species (mito-ROS), secondary to causative genetic mutation. However, exact mechanisms linking RyR2 dysfunction to mitochondrial injury remain unclear. We hypothesized that RyR2 hyperactivity activates the intermembrane space (IMS)-residing mitochondrial Ca 2+ -dependent protease , driving proteolysis of OPA1, a protein responsible for cristae flattening. This results in altered mitochondrial cristae diameter and mito-ROS production, exacerbating the arrhythmogenic CPVT phenotype. To test this, we created a unique CPVT RyR2-S2222L (+/-) rat model. Electron microscopy studies revealed a significant increase in cristae diameters in Langendorff-perfused CPVT rat hearts. Western blot analysis showed significantly reduced OPA1 expression in isolated CPVT VMs, suggesting that Ca 2+ -dependent proteolysis of OPA1 could underlie these ultrastructural changes. Pilot experiments suggest specific inhibition of via adeno-associated viral injection of IMS-targeted calpastatin (CAST, 10 12 VP, 4 weeks) can reduce ventricular tachycardia incidence of CPVT rats in vivo. Adenoviral expression of IMS-CAST in isolated VMs restored OPA1 expression levels and significantly improved intracellular Ca 2+ cycling in CPVT, suggesting a marked improvement in RyR2 function. Furthermore, genetic probes mtRCamp1h and HyPer-7 revealed that IMS- inhibition significantly improves mitochondrial matrix Ca 2+ homeostasis and mito-ROS in CPVT VMs, respectively. Importantly, these beneficial effects were lost in VMs with shRNA-mediated knockdown of OPA1. Our data suggest that enhanced activity of RyR2 promotes IMS- -mediated degradation of OPA1, resulting in mitochondrial structural damage that contributes to proarrhythmic remodeling in CPVT.
Abstract P2118: Modeling Arrhythmia Risk In Human Stem Cell Derived Cardiomyocytes
Authors: Malorie Blancard, K. A Fetterman, Davi M Lyra Leite, Lisa Dellefave-Castillo, Gregory G Webster, Megan Puckelwartz, Elizabeth M McNally, Alfred L George, Paul W Burridge
Journal: Circulation Research (2022)

In older (45+ years) populations, sudden cardiac death (SCD) is primarily caused by ischemic heart disease while in younger populations, SCD is often due to genetic causes. Despite recent advances in risk stratification based on clinical evaluation and genetic testing, our ability to predict SCD risk in the younger population remains inadequate. Implantable cardioverter defibrillators (ICDs) have been an essential intervention to reduce the number of out-of-hospital cardiac arrests in patients determined to be at risk of SCD. Nevertheless, one third of patients with an ICD receive inappropriate shocks and are exposed to infection without clear benefit. In addition, some children and young adults receive an ICD that will never deliver a shock even after decades of follow-up. No clear guidelines have been established to detect SCD-predisposing conditions due to cost, sensitivity, and specificity of testing modalities. Human iPSC-derived cardiomyocytes (hiPSC-CMs) are a widely recognized and reliable in vitro platform to study clinical phenotypes but have never been used in the context of SCD risk prediction. We hypothesize that we can establish an hiPSC-CMs cellular model to predict SCD risk. Sixty individuals were recruited and classified in one of five categories, ranging from healthy controls with no known cardiac disease (category 1) to individuals that show the highest SCD risk (category 5). These 5 categories are defined by 3 main parameters: 1) absence or presence of ICD, 2) whether the ICD was placed as primary or secondary prevention and 3) the number of shocks received after ICD implantation. hiPSCs were reprogrammed using blood samples and then differentiated into cardiomyocytes. Molecular and electrophysiology measurements were performed for the different risk categories using high-throughput systems. hiPSC-CMs were assayed by single-cell calcium imaging, microelectrode array and automated action potential and current recordings. In vitro measurements revealed that specific parameters such as field potential duration correlate with the SCD risk and outcome. In conclusion, this study will provide a cellular-based tool to determine patient-specific SCD risk in order to advance medical care for at-risk patients and their family members.
Abstract P3070: Distinct Inflammatory Milieu In Patients With Right Heart Failure
Authors: Bin Q Yang, Jason Liu, Joel D Schilling
Journal: Circulation Research (2022)

Introduction: Right heart failure (RHF) is associated with worse clinical outcomes in patients with heart failure (HF) and pulmonary hypertension. Previous studies have shown elevated circulating proinflammatory cytokines in patients with HF; however, no study has compared the inflammatory signature in patients with RHF to those with HF and preserved right ventricular (RV) function. Hypothesis: We predicted that patients with RHF would have a distinct inflammatory milieu compared to normal and HF patients. Methods: We recruited adult patients undergoing right heart catheterization (RHC) and excluded those with a history of transplant, autoimmune disease, malignancy, or infection. Patients underwent blood sampling during RHC and were classified into normal, HF, and RHF cohorts a priori . We then performed multiplex protein assay on serum targeting cytokines, chemokines, and growth factors. Results: A total of 43 patients were included. HF and RHF patients had similar demographics and cardiac indices, but the RHF cohort had elevated markers of congestion characterized by higher right atrial pressure and creatinine, and a trend towards higher bilirubin (Figure). Patients with RHF had elevated levels of select proinflammatory cytokines, chemokines, and growth factors. Of the factors measured, VEGF-A, soluble CD163, and CXCL12 were predictive of all-cause mortality and LVAD/transplant-free survival. Conclusion: Patients with RHF have a distinct proinflammatory signature compared to those with preserved RV function. VEGF-A, soluble CD163, and CXCL12 predicted clinical outcomes in an advanced HF population.
Abstract P3023: The Regulatory Role Of Mir-21 In Heart Failure With Preserved Ejection Fraction (hfpef)
Authors: Cody Juguilon, Molly Enrick, James Gadd, Yang Wang, Alyssa Clark, Chris Kolz, Vahagn A Ohanyan, William M Chilian, Liya Yin
Journal: Circulation Research (2022)

Introduction: Coronary microvascular dysfunction (CMD) is characterized by impaired endothelial-dependent vasodilation. These impairments are seen in diabetic cardiomyopathy, ischemia with no obstructive coronary artery disease, and heart failure with preserved ejection fraction (HFpEF), but detailed mechanisms have yet to be elucidated. Moreover, how microRNA (miR-21) regulates CMD in HFpEF is not entirely understood. Methods: miR-21 knockout and wild-type (WT) mice were fed a diet high in fat and sugar (HFHS) for 6 months and blood lipid and glucose were measured. Echocardiography and treadmill exercise exertion tests were performed to assess cardiac function. Myocardial blood flow (MBF) under stress was measured by contrast echocardiography or doppler after the treatment with different dosages of norepinephrine and mean arterial blood pressure was measured simultaneously by femoral pressure catheter. Cardiac fibrosis was detected using trichrome staining and molecular pathways were elucidated via gene and protein analysis. Results: Our preliminary data show decreased MBF during stress in WT mice fed a HFHS diet. While ejection fraction was not changed, cardiac index, stroke volume, and running distance were decreased. Furthermore, E/E’ ratio was increased in WT mice fed HFHS diet compared to the WT mice fed a chow diet, suggesting heart failure and impaired diastolic function with normal systolic function. Moreover, perivascular fibrosis was increased in the WT mice fed a HFHS diet compared to WT mice fed a chow diet. However, the ablation of miR-21 reversed all these changes in the mice fed a HFHS diet. Conclusions: miR-21 regulates CMD and ameliorated HFpEF. Further investigation will elucidate the pathways and mechanisms converging with miR-21 to regulate HFpEF.
Abstract P2041: Cytochrome P450 Reductase Prevents Cardiac Hypertrophy Through Crosstalk
Authors: Melina Lopez, Pedro F Malacarne, Ralf P Brandes, Flávia Rezende
Journal: Circulation Research (2022)

The cytochrome P450 reductase (POR) transfers electrons and thus drives the function of all cytochrome P450-dependent enzymes (CYP450). In the vascular system, the CYP450-POR system has been linked to vascular epoxyeicosatrienoic acids (EET) production and endothelial function. The functional importance of the endothelial CYP450 system in the heart, however, is unclear and was studied here, using a tissue-specific deletion approach. RNAseq revealed that murine cardiac endothelial cells express POR as well as numerous CYPs, which have been linked to different functions: CYP2 family members produce EETs, whereas CYP4 family generated omega fatty acids. Endothelial-specific, tamoxifen-inducible POR knockout mice (ecPOR -/- ) show endothelial dysfunction and increased hypertensive response to angiotensin II infusion. ecPOR -/- mice also exhibited cardiac hypertrophy, an increase in cardiomyocyte area, a reduced ejection fraction and an increased left ventricle size during systole (echocardiography) as compared to control animals. RNAseq of isolated cardiac endothelial cells revealed that deletion of POR was associated with a significant decrease in genes linked to unfolded protein response (Xbp1, Hspa5) whereas genes related to cardiac development were upregulated (Sox4, Gata4). Furthermore, cardiac myocytes showed a reduced expression of genes linked to mitochondrial ATP production (Sdhaf4, Mtx1, Coq10b).Collectively, our data suggest that loss of endothelial POR promotes cardiac hypertrophy potentially by modulating paracrine signals of endothelial cells to cardiac myocytes.
Abstract P3050: The Adropin-GPR19 Signaling Axis In Diabetic Cardiomyopathy
Authors: Bellina Mushala, Bingxian Xie, Dharendra Thapa, Michael Jurczak, Iain Scott
Journal: Circulation Research (2022)

Background: Diabetic cardiomyopathy (DCM) is a major complication of diabetes and has been recognized as a cause of heart failure independent of other common risk factors for cardiac disease. In DCM, increased free fatty acid availability and decreased myocardial glucose uptake lead to a reliance on fatty acid oxidation for ATP generation. This loss of metabolic flexibility can reduce cardiac plasticity in response to stress. Energetic inefficiency in diabetic hearts may have profound implications for cardiac function under conditions of increased workload, and therefore therapeutic approaches are warranted. Alleviating metabolic inflexibility, by promoting cardiac glucose utilization, has been proposed as a potential strategy to reverse cardiomyopathy in diabetic and obese patients. Adropin is a liver- and brain-secreted peptide hormone shown to regulate fuel metabolism in a number of tissues, including the heart. Adropin levels are significantly reduced in obese and diabetic human subjects, and this decrease is linked to increased adiposity, insulin resistance, and impaired glucose tolerance. Our lab recently showed that adropin treatment restores glucose oxidation activity in vivo by reducing the expression of the mitochondrial acetyltransferase enzyme GCN5L1. The reduction in GCN5L1 abundance altered the acetylation and activity of fuel metabolism enzymes to favor glucose utilization; however, the mechanism that underlies this effect remains unknown. Our data suggests that the class A orphan G-coupled protein receptor, GPR19, acts as a putative cellular receptor for adropin in cardiac cells to regulate mitochondrial bioenergetic output. Hypothesis: We hypothesize that adropin-GPR19 signaling regulates GCN5L1 expression, which in turn promotes the deacetylation and activity of pyruvate dehydrogenase to restore glucose utilization in the diabetic heart. Methods: We used a novel whole-body GPR19 knockout mouse to perform a preliminary characterization of the effects of GPR19 depletion on cardiac and whole-body physiology. Using in vivo metabolic approaches, we report that GPR19 KO mice exhibit sex-dependent glucose intolerance, and display markers of altered cardiac energy metabolism. Conclusions: These findings further define the fundamental role of the adropin-GPR19 signaling pathway in the regulation of metabolic homeostasis, and thus highlight a potential target for therapeutic interventions in DCM.
Abstract P1073: Pathways Regulating Cardiac Myocyte Proliferation
Authors: Zhenhe Zhang, George Davenport, Yiqiang Zhang, Robb W Maclellan
Journal: Circulation Research (2022)

Introduction: Several pathways have been shown to promote cardiomyocytes (CMs) proliferation and regeneration including the Hippo signaling pathway. Our lab demonstrated that selective depletion of H3K9me3 by lysine demethylase 4D (KDM4D) overexpression increases the proliferation of adult CMs (ACMs). However, all these stimulations are insufficient to promote robust ACM proliferation. The effect of combining these interventions on CM proliferation and myocardial regeneration remains unknown. Hypothesis: KDM4D-mediated CM-specific H3K9 demethylation and Hippo pathway inhibition have additive roles in promoting CM proliferation. Methods and results: miR-199 overexpression preferentially increased S-phase CMs (EdU + ) in cultured neonatal rat ventricular cardiomyocytes (NRVMs), while H3K9me3 demethylase KDM4D preferentially increased G2/M markers (phospho-H3). The combination of KDM4D and miR-199 increased total cell number of NRVMs compared to either alone. Since the effects of miR-199 on CM proliferation are mediated through inhibition of Hippo signaling, we inhibited the pathway directly via knock-down of Salvador Family WW Domain Containing Protein 1 (Sav1). Similarly, Sav1 inhibition also led to S-phase reactivation and additional cell cycle re-entry was seen when combined with KDM4D overexpression. Inducibly activating KDM4D (iKDM4D) in adult transgenic mice together with shRNA-mediated knock-down of Sav1 (iKDM4D+Sav1-sh) resulted in a significant increase in cycling CMs compared to either intervention alone. In vitro gene expression analysis demonstrated that KDM4D preferentially induced expression of genes regulating late (G2/M) phases of the cell cycle while miR-199 and si-Sav1 preferentially upregulated genes involved in G1/S phase. RNA-seq and promoter analysis demonstrated that KDM4D and Hippo signaling pathway regulate CMs proliferation through different transcriptional pathways. KDM4D upregulated E2F1 and FoxM1 expression, whereas miR-199 and si-Sav1 induced Myc. Conclusions: KDM4D additively induces CMs proliferation with the Hippo-Yap1 pathways. This may have important implications for strategies that target cardiac regeneration in treating heart disease.
Abstract P2068: The Nuclear Transcription Factor Y Controls Cell-cycle And Metabolic Gene Transcription During Cardiac Development
Authors: Miao Cui, Ning Liu, Rhonda S Bassel-Duby, Eric N Olson
Journal: Circulation Research (2022)

The Nuclear Transcription Factor Y (NF-Y) is a trimeric complex composed of subunits NF-Ya, NF-Yb, and NF-Yc. While all three subunits are expressed across tissues and cell types, the activity of the NF-Y complex is largely dependent on the expression of its DNA-binding subunit NF-Ya. NF-Y functions as a pioneer factor in regulating gene transcription, but its cardiac-specific role is poorly understood. Using single-nuclear RNA sequencing, we previously showed that NF-Ya is expressed in regenerative cardiomyocytes in neonatal mouse hearts and its expression is downregulated after birth. Given its high expression in embryonic hearts, we hypothesized that it plays a role during cardiac development. We discovered that mice with cardiomyocyte-specific deletion of NF-Ya using alpha-MHC-Cre die before birth. At embryonic day 15, the knockout hearts showed myocardial hypoplasia and noncompaction with decreased cardiomyocyte proliferation. Interestingly, the expression of genes regulating oxidative and glycolytic metabolism as well as genes encoding fetal contractile protein isoforms were downregulated in the knockout hearts. Using chromatin immunoprecipitation and reporter assays, we found that NF-Ya directly regulates the transcription of cell-cycle and metabolic genes while indirectly controlling fetal gene expression. Combined single-nuclear RNA and ATAC sequencing analyses revealed a precocious maturation trajectory in cardiomyocytes from NF-Ya knockout embryos, leading to a reduced reservoir of immature regenerative cardiomyocytes in the fetal heart. Our study reveals cellular heterogeneity of fetal cardiomyocytes and the role of NF-Y in regulating cardiac growth and maturation before birth. Our study also identified a previously unrecognized transcriptional control mechanism of metabolic genes controlled by the NF-Y complex and highlights the importance of both oxidative and glycolytic metabolism during fetal heart development and maturation.